Pretty complicated

#!/bin/bash

# List contents of ~/.var/app/
files=$(ls -1 ~/.var/app/)

# Loop through each element of the folder
for file in $files; do
    # Set the name as a variable
    app_name="${file##*/}"

    # Check if a flatpak app of that name is installed
    if ! flatpak list 2> /dev/null | grep -qw $app_name; then
        # Ask the user to delete the folder
        read -p "The app $app_name is not installed. Do you want to delete its folder? (y/n): " choice
        case "$choice" in
            [Yy]* )
                # Remove the folder recursively
                rm -rf ~/.var/app/$file;;
            [Nn]* )
                echo "Skipping deletion of $app_name folder.";;
            * )
                echo "Invalid input. Skipping deletion of $app_name folder.";;
        esac
    fi
done

echo "All Apps checked."